The facelifted BMW 7 Series is the latest shot in the relentless game of luxury-limousine one-upmanship.

Four years after the launch of Munich’s fifth-generation flagship, the ‘Life-Cycle Impulse’ (BMW-speak for a mid-life update) is designed to do exactly that. With new and upgraded powertrains and added tech features – albeit few that we haven’t already seen elsewhere in the BMW family or from the brand’s competitors – the 7 Series needs its ‘impulse’ to fight against the newly launched Lexus LS and forthcoming all-new Mercedes-Benz S-Class, which is here in 12 months.

Perhaps more than with pioneering gadgetry, the 7 Series showcases BMW’s – and let’s not overstate this – brilliant engine technology. The revised 7 Series range is up to 25 per cent more efficient than the one it replaces. All models now benefit from auto stop-start and brake energy regeneration technology, as well as an Eco Pro driving mode with a ‘coasting’ function that decouples the engine for more economical cruising between 50-160km/h – all clever features, yet not ones that are exclusive to the 7 Series or BMW.

The 750i, the single V8-powered 7 Series, now features an uprated 330kW/650Nm twin-turbocharged 4.4-litre petrol engine, and sprints from 0-100km/h in 4.8 seconds, putting it neck and neck with the Porsche 911. With a combined cycle fuel consumption of 8.6 litres per 100km, the Beemer is also more fuel efficient than the slippery coupe, despite its 1960kg kerb weight making it more than half a tonne heavier.

The entry-level 730d consumes just 5.6L/100km, which, remarkably, makes it more fuel efficient than a Nissan Micra. Meanwhile, the 190kW/560Nm 3.0-litre six-cylinder diesel’s 6.1-second 0-100km/h ability allows it to hassle hot-hatches off the line – impressive for a car that puts more than five metres between its restyled kidney grille and tweaked tail-lights.

BMW Australia has also added the ActiveHybrid 7 to the line-up (arriving in December), which – at 6.8L/100km – is 14 per cent more fuel efficient than the 740i variant on which it’s based, yet no slower from 0-100km/h (5.7 seconds).

Improved dynamic performance was another focus of the update, with rear self-levelling air suspension – previously only offered on long-wheelbase variants – now standard across the range. Pre-update standard-wheelbase models with the more basic multi-link rear suspension set-up were criticised for their overly touchy and harsh ride. The ride in the new 7 Series is firm but remains comfortable and composed when ironing out most bumps – at least on the chosen roads of BMW’s launch program. Potholes and larger surface imperfections can sometimes elicit a less refined thump.

The BMW 7 Series’ electric power steering exhibits a slight vagueness at lower speeds but becomes more consistent and dependable as you hit the highway or find some corners. Surprisingly, the newly re-suspended Bavarian revels in them. The lighter 730d and 740i variants feel the most nimble and best balanced of the bunch. The extra weight over the front of the bigger-engined models – particularly the 760Li, which is 350kg heavier overall than the 740i – is noticeable but not significant enough to make either car feel cumbersome.

Extra firmness and weight – as well as additional throttle responsiveness and sportier shift patterns – are dialled in as you scroll up through the Driving Dynamics Control menu, progressing from Eco Pro, Comfort+, Comfort and Normal to the more playful Sport and Sport+ settings.

While definitely not a sports car, the BMW 7 Series is a blast to punt along twisty roads, with masses of torque available just north of idle regardless of the engine (730d: 560Nm at 1500rpm, 740i: 450Nm at 1300rpm, 750i: 650Nm at 2000rpm, 760Li: 750Nm at 1500rpm).

While the thunderous growl of the 760Li’s 400kW 6.0-litre twin-turbo V12 is addictive, the standout aural performer is the 235kW single-turbo 3.0-litre inline six in the 740i; its meaty yet metallic wail could be mistaken for a V8 from either behind the wheel or outside. The 730d’s 190kW 3.0-litre six-cylinder diesel emits a tell-tale (albeit muted) rumble at start-up and idle, but is quiet and effortlessly refined once on the move.

It may feel barge-like around the city and when trying to park, but the BMW 7 Series becomes less intimidating as you up the pace and become more engrossed with its dynamic aptitude.

An encompassing cabin helps here, with the dashboard, console and doors wrapping close to your body, the centre stack and gear stick angled towards the driver, and the brilliantly supportive new driver’s seat holding you comfortably behind the thick-rimmed steering wheel.

The interior finish is first-class as expected, with an elegant combination of stitched leathers, smooth plastics and polished metals, although it’s let down by a few ergonomic shortcomings. Internal storage is limited, with tiny door pockets, a shallow centre console and a glove box that is practically filled by the owner’s manual. The 500-litre boot will swallow plenty of gear, although it’s somewhat narrow and 35 litres smaller than that of a Ford Falcon. The ActiveHybrid 7’s rear-mounted lithium-ion batteries cut the petrol-electric model’s cargo capacity to 360 litres.

There’s also no seatbelt height adjustment for the driver and front passenger, and BMW charges $600 for the digital multifunctional instrument display, which changes colour and content to match your driving mode setting.

While long options lists have become a trademark of the German marques, the customer who parts with $391,500 for a 760Li may find it a bit stiff to be forced to dig deeper into their Armani jeans for basic features like a music interface for iPhone integration ($220), digital radio ($950), heated steering wheel ($500) and a tyre pressure monitor ($700).

Many of the 7 Series’ active safety systems are optional for the 730d and 740i variants (which are expected to account for roughly two-thirds of total sales), including Lane Change Warning System ($1400), Driving Assistant Plus with active cruise control ($5500), Night Vision with Dynamic Light Spot ($4700) and the Surround View 270-degree camera system ($1300).

Other options include heated and ventilated reclining Comfort Seats ($6500) and the Rear-Seat Entertainment System Professional ($6200), which features an iDrive controller in the centre armrest and two 9.2-inch screens on the front seatbacks for watching live TV, DVDs, playing games or surfing the internet.

Comfort in the outer rear seats is high even in the standard pews, although the hard centre seat is best for short trips only – somewhat disappointing for a car designed for chauffeuring VIPs. Legroom is generous even in standard-wheelbase form but six-footers just scrape in for headroom.

BMW spoke at length about the 7 Series’ new LED lighting technologies on the launch. High-Beam Assistant identifies oncoming traffic and partially masks the headlights to create dark spots, eliminating the danger of dazzling other drivers while continuing to fully illuminate the rest of the car’s surroundings. In contrast, Dynamic Light Spots are used to pinpoint pedestrians at night, sending out a focused, more intense beam to highlight their presence on the road.

Benchmark efficiency, improved ride refinement and some new tech features should be enough for the BMW 7 Series to remain competitive until the all-new model launches in around 2016. But with the new S-Class here next year, it may not be enough to keep the 7 Series at the pointy end of the competition…